Human immunodeficiency virus (HIV) -1 the etiologic agent of AIDS is the fastest growing cause of death in men and women of reproductive age. In the absence of effective treatment as well as anti-HIV therapy or vaccine, new emphasis has been placed on the development of anti-HIV agents capable of reducing this epidemic. We have prepared a very potent anti-HIV nucleoside analog of d4T, DDE113 (Stampidine (hard gelatine encapsulated form)). This nucleoside analog is significantly more potent than stavudine and AZT for many primary clinical human HIV isolates. In the further development of DDE113 and related compounds as potential anti-HIV agents it is now necessary to examine issues related to the formulation, specifically determining the optimal dosage forms for potential use in clinical trials and further commercial development. We will monitor dissolution of DDE113 in acid and alkaline condition using different formulations, and then use the analysis of variance/non-linear regression models to choose the formulation with the most favorable dissolution characteristics. [unreadable] [unreadable]